Flashcards in Waves Deck (25):
Give examples of transverse waves
Light, secondary waves and all of the EM waves
Give examples of longitudinal waves
How do transverse waves travel?
At 90 degrees to the direction of the vibration
How do longitudinal waves travel?
In the same direction as the vibration
What are the conditions for refraction?
Light must enter the object at an angle greater than 0 degrees and less than 90 degrees
The bending of light
As light passes from air to glass, is the refracted ray bent towards or away from the normal?
As light passes from glass to air, is the refracted ray bent towards or away from the normal?
What is the angle of incidence equal to?
The angle of reflection
Why does light bend towards the normal when passing from a less dense medium into a denser medium?
It slows down
Why does light bend away from the normal when passing from a more dense medium into a less dense medium?
It speeds up
What happens when the angle of incidence is greater than the critical angle?
Total internal reflection
What are the 2 conditions for total internal reflection?
1. The angle of incidence is > than the critical
2. Light travels from a denser medium to a less dense medium
Name 2 things that use total internal reflection
Endoscopes and optical fibres
What instrument is used to detect seismic waves?
Which seismic wave is fastest?
Which seismic wave can travel through liquids and solids?
Which seismic wave is second fastest?
Which seismic wave can travel through solids only?
Which seismic wave is slowest?
Which seismic wave is the most destructive and why?
Surface as they travel around the Earth's surface and may produce a rolling motion
How have scientists used effects of earthquakes to find the Earth's structure?
S wave shadow zone suggests that part of the Earth's core is liquid
Positions that waves are detected suggest that the density of rock changes, as waves are refracted
If seismic waves are bent in curves, what does it suggest about the density of rock in the inner Earth?
It changes gradually
If seismic waves are bent sharply, what does it suggest about the density of rock in the inner Earth?
It changes suddenly